                             :line ~(:line (meta form))}
                            nil))
                  nxt))
-        `(SimpleContainer ~r {:generator given
+        `(SimpleContainer ~r {:generator 'given
                               :line ~(:line (meta &form))
                               :form '~&form}
                           nil)))))

  `(let [active# ~active
         contexts# ~contexts
         merged# (reduce open-context active# contexts#)
         ~states (map merged contexts#)]
     (try
      ~@body
      (finally


;;; Public API

(defmacro is
  "A series of assertions.  Each assertion is a simple expression,
  which will be compiled into a function.  A string will be attached
  as :doc metadata on the following assertion."
